Chapter 15 - Ears

Question 1

Binaural interaction at the level of the brain stem permits…

Answer 1

identification and location of the direction of the sound

Question 2

The labyrinth of the inner ear is responsible for maintaining the body’s…

Answer 2

equilibrium

Question 3

If the tympanic membrane has white dense areas, the examiner suspects…

Answer 3

scarring from recurrent ear infections

Question 4

the pars flaccida

Answer 4

The small, slack, superior section of the tympanic membrane

Question 5

annulus

Answer 5

the outer fibrous rim of the drum

Question 6

Lymphatic drainage of the external ear flows to which nodes?

Answer 6

parotid, mastoid, and superficial cervical nodes

Question 7

The middle ear has three functions:

Answer 7

(1) it conducts sound vibrations from the outer ear to the central hearing apparatus in the inner ear
(2) it protects the inner ear by reducing the amplitude of loud sounds
(3) its eustachian tube allows equalization of air pressure on each side of the tympanic membrane so that the membrane does not rupture (e.g., during altitude changes in an airplane)

Question 8

bony labyrinth

Answer 8

holds the sensory organs for equilibrium and hearing

1. Vestibule
2. Semicircular Canals
3. Cochlea

Question 9

Vestibule & Semicircular Canals

Answer 9

compose the vestibular apparatus

Question 10

Cochlea

Answer 10

contains the central hearing apparatus

Question 11

The function of hearing involves the auditory system at three levels:

Answer 11

peripheral, brainstem, and cerebral cortex

Question 12

Peripheral level of hearing

Answer 12

the ear transmits sound and converts its vibrations into electrical impulses, which can be analyzed by the brain.

Question 13

Brainstem level of hearing

Answer 13

binaural interaction, which permits locating the direction of a sound in space as well as identifying the sound

Question 14

Cerebral cortex level of hearing

Answer 14

interpret the meaning of the sound and begin the appropriate response.

Question 15

organ of Corti

Answer 15

the sensory organ of hearing

Question 16

What are the 2 pathways of hearing?

Answer 16

Air Conduction (AC) - most efficient
Bone Conduction (BC)

*vibration are transmitted to inner ear TO cranial nerve VIII

Question 17

2 types of hearing loss:

Answer 17

Conductive & Sensorineural

Question 18

Conductive hearing loss

Answer 18

involves a mechanical dysfunction of the external or middle ear.

partial loss because the person is able to hear if the sound amplitude is increased enough to reach normal nerve elements in the inner ear.

may be caused by: impacted cerumen, foreign bodies, a perforated tympanic membrane, pus or serum in the middle ear, and otosclerosis (a decrease in mobility of the ossicles).

Question 19

sensorineural hearing loss

Answer 19

signifies pathology of the inner ear, cranial nerve VIII, or the auditory areas of the cerebral cortex.

increase in amplitude may not enable the person to understand words.

may be caused by presbycusis

Question 20

presbycusis

Answer 20

a gradual nerve degeneration that occurs with aging, and by ototoxic drugs, which affect the hair cells in the cochlea.

Question 21

Otosclerosis

Answer 21

common cause of conductive hearing loss in young adults between the ages of 20 and 40 years.

gradual hardening that causes the footplate of the stapes to become fixed in the oval window, impeding the transmission of sound and causing progressive deafness.

Question 22

Otitis media, or OM (middle ear infection)

Answer 22

occurs because of obstruction of the eustachian tube or passage of nasopharyngeal secretions into the middle ear

Question 23

Cerumen is genetically determined to be of two major types:

Answer 23

(1) dry cerumen, which is gray and flaky and frequently forms a thin mass in the ear canal; and
(2) wet cerumen, which is honey brown to dark brown and moist.

Chromosome 16 holds one gene trait determining the wet or dry phenotype.

The wet cerumen phenotype occurs more often in Caucasians and African Americans

dry cerumen is more frequent in Asians and American Indians.

The presence and composition of cerumen are not related to poor hygiene. Take caution to avoid mistaking the flaky, dry cerumen for eczematous lesions.

Question 24

Otalgia

Answer 24

(earache) may be directly due to ear disease or may be referred pain from a problem in teeth or oropharynx.

Question 25

Otorrhea

Answer 25

(discharge) suggests infected canal or perforated eardrum

Question 26

xternal otitis

Answer 26

purulent, sanguineous, or watery discharge

Question 27

Acute otitis media with perforation

Answer 27

purulent discharge.

Question 28

Cholesteatoma

Answer 28

dirty yellow/gray discharge, foul odor.

Question 29

Recruitment

Answer 29

a marked loss when speech is at low intensity, but sound actually becomes painful when speaker repeats in a loud voice.

Question 30

Microtia

Answer 30

ears smaller than 4 cm vertically

Question 31

macrotia

Answer 31

ears larger than 10 cm

Question 32

Test Hearing Acuity: Audiometer

Answer 32

Battery powered machine that emits sounds. When patient hears sound, raise a hand/finger to signify. Rate results

Question 33

Test Hearing Acuity: Whispered Voice Test

Answer 33

Test one ear at a time while masking hearing in the other ear to prevent sound transmission around the head.

place one finger on the tragus and rapidly pushing it in and out of the auditory meatus. Shield your lips so the person cannot compensate for a hearing loss (consciously or unconsciously) by lip reading or using the “good” ear. With your head 1 to 2ft from the person’s ear, exhale and whisper slowly a set of 3 random numbers and letters, such as “5, B, 6.”

Question 34

Test Hearing Acuity: Tuning Fork Test

Answer 34

Tuning fork tests measure hearing by air conduction (AC) or by bone conduction (BC), in which the sound vibrates through the cranial bones to the inner ear.

Question 35

THE VESTIBULAR APPARATUS: The Romberg test

Answer 35

assesses the ability of the vestibular apparatus in the inner ear to help maintain standing balance. Because the Romberg test also assesses intactness of the cerebellum and proprioception

Question 36

Frostbite

Answer 36

Reddish blue discoloration and swelling of auricle after exposure to extreme cold. Vesicles or bullae may develop, the person feels pain and tenderness, and ear necrosis may ensue.

Question 37

Swimmer’s Ear

Answer 37

(Otitis Externa) An infection of the outer ear, with severe painful movement of the pinna and tragus, redness and swelling of pinna and canal, scanty purulent discharge, scaling, itching, fever, and enlarged tender regional lymph nodes. Swimming causes canal to become waterlogged and swell; skinfolds are set up for infection.

Prevent by using rubbing alcohol or 2% acetic acid eardrops after every swim.

Question 38

Cellulitis

Answer 38

Inflammation of loose, subcutaneous connective tissue. Shows as thickening and induration of auricle with distorted contours.

Question 39

Tophi

Answer 39

Small, whitish yellow, hard, nontender nodules in or near helix or antihelix; contain greasy, chalky material of uric acid crystals and are a sign of gout.

Question 40

Exostosis

Answer 40

More common than osteoma. Small, bony hard, rounded nodules of hypertrophic bone, covered with normal epithelium. They arise near the drum but usually do not obstruct the view of the drum. They are usually multiple and bilateral. They may occur more frequently in cold-water swimmers.

no treatment, although it may cause accumulation of cerumen, which blocks the canal.

Question 41

Furuncle

Answer 41

Exquisitely painful, reddened, infected hair follicle. It may occur on the tragus on the cartilaginous part of ear canal. Regional lymphadenopathy often accompanies a furuncle.

Question 42

Polyp

Answer 42

Arises in canal from granulomatous or mucosal tissue; redder than surrounding skin and bleeds easily; bathed in foul, purulent discharge; indicates chronic ear disease. Benign, but refer for excision.